Floating thermometer



Sept. 5, 1950 L. F. CHANEY 2,520,911

FLOATING THERMOMETER Filed March 2, 1946 Patented Sept. 5, 1950 UNITED STATES PATENT OFFICE FLOATING THERMOMETER Lee F. Chaney, Springfield, Ohio, assignor to The Ohio Thermometer Company, Springfield, Ohio, a corporation of Ohio Application March 2, 1946, Serial No. 651,512

1 Claim. 1

This invention pertains to therometers of the floating type, for example dairy thermometers and the like.

Such thermometers are ordinarily ballasted by a body of lead shot or other comparatively heavy material, which is confined to one end of the thermometer by a wax insert plug. The present invention contemplates so shaping the thermometer ciasing as to prevent displacement of the insert plug and consequent release of the ballast material.

The object of the invention is to improve the construction as well as the means and mode of construction of the casing of such thermometer, whereby they may be economically manufactured, and will confine the ballast material to a prescribed area by interlocking the insert plug against displacement.

With the above primary and other incidental objects in view as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, and parts and combinations thereof, and the mode of operation, or their equivalents, as hereinafter described or illustrated in the accompanying drawings.

The single figure of the drawing shows a typical floating thermometer, the casing of which is shaped to embody the present invention.

Floating thermometers of the instant type embody an elongated tubular casing l of glass in which are enclosed an indicator tube 2, containing a column of mercury or alcohol and a corresponding graduated scale 4 with which the indicator tube 2 cooperates. In the lower end of the casing, wherein the bulb 5 of the indicator tube is located, there is also confined a body 6 of ballast material of small lead shot or other material of high specific gravity surmounted by an insert plug '1 of wax or the like. Such is the conventional floating type thermometer, which, per se, forms no part of the instant invention.

The casing I is ordinarily of straight cylindrical form terminating in a uniformly tapered extremity merging into the cylindrical walls of the casing without interruption. The wax insert plug 1, which is poured on top of the body 6 of ballast material while molten, sometimes becomes loosened especially when the instrument is used in warm liquids.

This permits the insert plug 1 to shift its position when in the conventional uniformly tapered terminal of a floating thermometer, thus releasing the ballast material within the casing. The

present invention consists in providing a peripheral restriction 8 in the thermometer casing, immediately above the zone of the insert plug 1. The neck 8 thus formed is of somewhat smaller dimension than the insert plug 1 and thus prevents the longitudinal displacement of the plug 1 within the casing I, even though loosened therein. The plug I is of such size that it can not pass through the neck or constriction 8 and consequently must retain its position, and continue to confine the body of ballast material 6.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise the preferred form of several modes of putting the invention into efiect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claim.

Having thus described my invention, I claim:

A thermometer of the floating type wherein a casing having a tapered lower extremity encloses a thermometer tube, and a body of loose ballast material confined to the tapered end of the easing about the bulb of said thermometer tube by an inserted plug, characterized by a peripheral contraction of the casing above the level of the ballast confining plug to prevent accidental displacement thereof/and release of the ballast material.

LEE F. CHANEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 493,197 Tagliabue Mar. 7, 1893 1,172,647 Voiges Feb. 22, 1916 1,316,780 Freas Sept. 23, 1919 1,907,103 Harris May 2, 1933 2,051,540 Chaney Aug. 18 1936 

